General description of procedure, equipment, technique

Role of percutaneous coronary intervention in the treatment of patients with chronic ischemic heart disease

The goals of percutaneous coronary intervention (PCI) for revascularization of patients with coronary artery disease (CAD) are: (1) to improve survival time and/or (2) to relieve symptoms. PCI recommendations in this section have been formulated specifically for patients with stable ischemic heart disease (SIHD). Moreover, when discussing options for revascularization with the patient, the indication for the procedure and its objectives (to improve symptoms and/or to improve survival time) should be made clear.

Most coronary revascularization in general and PCI recommendations have been based on angiographic criteria of a “significant” stenosis: >70% diameter narrowing and >50% for left main (LM) CAD. More recently, physiologic criteria, such as an assessment of fractional flow reserve (FFR), has been used in deciding when revascularization is indicated. An FFR <0.80 is also considered to be “significant.”

A heart team approach involves a multidisciplinary team, composed of an interventional cardiologist and a cardiac surgeon to review PCI or coronary artery bypass graft surgery (CABG) options, and is highly desirable and associated with improved clinical outcomes.

Role of coronary angiography

Coronary angiography is the “gold standard” to visualize and characterize the coronary anatomy, including the severity of epicardial coronary obstructions, presence of collateral flow, and also an estimate of coronary flow. Coronary angiography in patients with stable ischemic heart disease (SIHD) has two primary objectives:

Assessment of the risk of death and future cardiovascular events based on the severity and distribution of coronary obstruction(s)

The role of PCI for improvement of survival time is not clear in patients with 3- and 2-vessel CAD, with or without proximal left anterior descending artery (LAD) disease (IIb). It is of also uncertain benefit with respect to a survival benefit in patients with only proximal LAD disease, although in clinical practice PCI is often preferred with 1-vessel proximal LAD disease (IIb). CABG overall should be preferred over PCI in patients with diabetes mellitus (DM) and multivessel CAD (IIa).

PCI in SIHD is not indicated (III) in patients with <70% angiographic stenosis and/or FFR >0.80 or no/mild ischemia on noninvasive testing.

PCI for improvement of symptoms:

PCI is indicated (I) for relief of symptoms associated with significant stenosis (>70% diameter narrowing of non-LM, >50% LM CAD) or FFR <0.80 in lesions amenable to PCI and unacceptable angina despite guideline-directed medical therapy or in whom such medical therapy cannot be implemented secondary to contraindications, patient preferences, or unacceptable side effects.

PCI is also indicated in patients with unacceptable angina despite guideline-directed medical therapy with prior CABG.

In patients with unacceptable angina despite guideline-directed medical therapy and complex/3-vessel CAD, PCI may be performed for relief of angina (IIa); however, CABG is preferred, especially in patients with DM.

PCI in SIHD is not indicated (III) in patients with <70% angiographic stenosis and/or FFR >0.80 or no/mild ischemia on noninvasive testing.

Particular patient populations:

Diabetes mellitus: In patients with multivessel disease who also have diabetes, it is reasonable to choose CABG (with LIMA) over PCI.

Chronic kidney disease (CKD): There is evidence from observational studies and meta-analyses to indicate improved survival with revascularization compared with medical therapy in patients with CKD and multivessel CAD. It is important to indicate that CABG may be preferable over PCI and both revascularization strategies may be associated with higher preprocedural complications compared to patients without CKD.

Left ventricular dysfunction: The magnitude of clinical benefit for improvement in survival time with coronary revascularization in patients with left ventricular dysfunction favors CABG, especially in patients with multivessel CAD, DM, and CKD).

Completeness of coronary revascularization: In patients with multivessel CAD, PCI provides complete revascularization in <70% of patients, which is lower than lower than that provided by CABG. Whether in SIHD patients this influences outcomes is less clear.

Women: Data from COURAGE suggest that the benefits of guideline-based medical therapy alone in comparison with medical therapy plus PCI were similar for men and women. Long-term outcomes of revascularization appear to be less favorable among women than men. The risk of procedural complications also appears to be significantly higher in women.

Older adults: Data on PCI for SIHD in patients >75 years of age are sparse; nevertheless, they are a growing segment of our patient base. These patients have a mortality rate and decisions to recommend PCI should be undertaken only after careful consideration of patient preferences, functional capacity, quality-of-life and end-of-life issues, as well as therapeutic alternatives.

Indications and patient selection

It is important to indicate that coronary arteriography in patients with SIHD may be considered either as an initial testing strategy or after an initial workup with non-invasive test(s).

As an initial testing strategy, coronary angiography is indicated:

In patients with SIHD who have survived sudden cardiac death or potentially life-threatening ventricular arrhythmia (Class I). In these patients, coronary angiography should be performed promptly to assess cardiac risk (Class I)

In patients with SIHD who develop signs and symptoms of heart failure. These patients should also undergo should coronary angiography an part of their initial evaluation for risk assessment (Class I)

After an initial workup with noninvasive test(s), coronary angiography is indicated:

In patients with SIHD whose clinical characteristics and noninvasive test results indicate a high likelihood of severe myocardial ischemia and when the benefits of an invasive assessment by coronary angiography are deemed to exceed risk (Class I)

In patients with SIHD with either inconclusive noninvasive test results or in whom noninvasive testing is contraindicated or inadequate (Class IIa)

In patients with SIHD with preserved LV function (EF ˃50%) and intermediate risk criteria on noninvasive testing, who deem their quality of life unsatisfactory due to angina despite a conscientious trial of evidence-based medical therapy (Class IIa)

There are important clinical scenarios when coronary angiography in patients with SIHD may not provide any benefit and the risk of the procedure outweighs the risk associated with this invasive procedure. The reader should take careful note of the following clinical scenarios that have received a Class III recommendation by the ACC/AHA guidelines:

Patients without any evidence of ischemia on noninvasive testing (Class III)

Patients who are not revascularization candidates or choose not to undergo coronary revascularization procedures (Class III)

Contraindications

N/A

Details of how the procedure is performed

Detailed description of how the procedure is performed; patient preparation; preoperative assessment; aftercare

This section primarily focuses on post-PCI dual anti-platelet therapy (DAPT) and post-PCI noninvasive stress testing in patients with SIHD, with the class of recommendation indicated within brackets.

DAPT:

Aspirin therapy should be continued indefinitely after PCI (I) and it is reasonable to use 81 mg/day maintenance doses of aspirin over higher doses (IIb).

In patients receiving drug eluting stents (DES) for SIHD, clopidogrel 75 mg/day should be given for at least 12 months if patients are not at high risk of bleeding (I).

In patients receiving bare metal stents (BMS) for SIHD, clopidogrel should be given for a minimum of 1 month and ideally up to 12 months, unless the patient is at increased risk of bleeding; then it should be given for a minimum of 2 weeks (I).

Patients should be counseled on the importance of compliance with DAPT, and that therapy should not be discontinued before discussion with their cardiologist (I).

Clinical follow-up:

Routine periodic stress testing of asymptomatic patients after PCI without specific clinical indications should not be performed (III).

Clinicians should follow-up with patients’ post-PCI for SIDH with assessment of symptoms and clinical function, surveillance for complications of SIHD, including heart failure and arrhythmias and assessment of the adequacy of and adherence to recommended lifestyle changes and medical therapy (I).

Interpretation of results

N/A

Performance characteristics of the procedure (applies only to diagnostic procedures)

N/A

Outcomes (applies only to therapeutic procedures)

N/A

Alternative and/or additional procedures to consider

CABG confers a survival benefit over medical therapy in patients with LM CAD. Studies that provide high-quality evidence that compare PCI with medical therapy in patients with “unprotected” LM CAD do not exist.

CABG and PCI confer similar survival advantages for patients with disease in the proximal segment of the LAD artery.

Hybrid coronary revascularization (defined as the planned combination of LIMA-to-LAD artery grafting and PCI of ≥1 non-LAD coronary arteries) is reasonable in patients with limitations to traditional CABG (IIa), such as heavily calcified proximal aorta or poor target vessels for CABG (but amenable to PCI) or unfavorable LAD artery for PCI (i.e., excessive vessel tortuosity or chronic total occlusion).

In patients SIHD at low or intermediate risk, it is safe to defer revascularization and pursue evidence-based medical therapy, because neither survival nor adverse cardiac events are averted by proceeding immediately to PCI or CABG.

Alternative and/or additional procedures to consider

Despite the “gold standard” status of coronary angiography for delineating epicardial coronary anatomy and severity/distribution of coronary artery disease, the reader should be aware of its limitations:

Acquisition of images during coronary angiography may be suboptimal making interpretation unreliable or impossible. Thus, proper image acquisition is quintessential and can significantly impact patient care

Despite the presence of automated off-line quantitative assessments of coronary anatomy and obstructions, most coronary angiograms in clinical practice are analyzed by visual examination and thus subject to interobserver variability

Coronary angiography alone can only provide anatomic information of the epicardial coronary vessels, without reliably indicating the functional significance of given coronary stenoses

Coronary angiography provides an accurate assessment of the epicardial coronary lumen and not of the burden or the characteristics of the atherosclerotic plaque in the vessel wall, which relates closely to a patients’ risk of future myocardial infarction

However, multiple other modalities are available to the angiographer to assist in accurately determining the significance of a coronary lesion and/or characteristics of coronary atherosclerotic plaques (i.e., fractional flow reserve, or FFR assessment and intravascular ultrasound).

Moreover, with improvements in temporal and spatial resolution, as well as volume coverage of computed tomographic imaging of coronary vessels (CCTA), a noninvasive evaluation of coronary arteries with CCTA is now possible with a high degree of image quality.

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